Optimization and characterization of in situ epoxidation of chicken fat with peracetic acid

摘要

The objective of this study was to optimize the epoxidation of chicken fat. This experiment was carried out with peracetic acid generated in situ by using hydrogen peroxide and acetic acid. A response surface design of the BoxBehnken type was used, with two response variables, the percentage of double bond conversion and the epoxy content. The factors evaluated were temperature (60, 70, 80 degrees C), catalyst (H2SO4) (0.5, 0.75, 1 w/w), moles of H2O2 (1, 1.5, 2) and moles of acetic acid (0.5, 1, 1.5). The optimum conversion into oxirane (94%) and conversion of iodine (98%) was at the condition of 60 degrees C reaction temperature, acetic acid to unsaturation mole ratio of 0.54, hydrogen peroxide to unsaturation mole ratio of 2.0 for 6 h. The optimal reaction conditions generated an epoxidated fat without by-products. An increase in viscosity was obtained from 32 to 91 cSt at 40. C, an improvement in oxidative stability from 0.39h to 3h at 110 degrees C, compared to raw material. Therefore, the physicochemical result obtained in the epoxidation of chicken fat complies with the ISO VG 100 grade for industrial application. In rheological and tribological characterization epoxide product behave like newtonian fluids at different temperatures and a coefficient of friction was stable over time, typical of commercial lubricants, also epoxide produced was considered as "easy biodegradability" since at 13 days degraded in a 60%.